Ants Trapped Inside Abandoned Nuclear Bunker Develop A Unique Society

The fact that ants are fascinating insects has been known for some time. The tiny creatures that make their way around using their built-in GPS, survive floods by morphing into living rafts and are even reputed to predict earthquakes. Now, scientists have discovered a colony of wood ants living in a dark underground barren bunker despite having no apparent source of food.

Built by the Soviet Union to store nuclear weapons, the bunker located in in Templewo, Poland, was abandoned after the end of the Cold War. Eventually, a large colony of wood ants took up residence in the soil above, building a 60-cm high nest directly over the bunker’s vertical ventilation pipe. As years passed, the metal covering on the pipe eroded, leaving behind a gaping hole that thousands of worker ants accidentally slip into each day, as they go about their daily chores.

Polish Academy of Sciences zoologist Wojciech Czechowski and his team began studying the underground colony in 2013, after they were discovered by colleagues researching the population of bats in the bunker. The scientists, who published their observations in the Journal of Hymenoptera in late August, say that besides the bats and mites that feed on the dead ants, there are no other visible sources of food in the bunker. This means that the insects live in a state of near starvation and are probably dying at a rate faster than they would at the surface.

In July 2015, the researchers disturbed part of the ant mound in search of larvae, pupae, empty cocoons, and queens.They found nothing, leading them to suspect that the lack of food and cold temperatures made reproduction impossible and that the group tending the nest is entirely composed of non-reproductive female workers. Their population is replenished every year, by a new rain of unfortunate ants, that slide down the ventilation shaft, never to see the light of day again.

The researchers say that when they returned in January 2016, the mound had been repaired. It appears that despite the inhospitable conditions and having no queen or ant brood to care for, the worker ants do not stop constructing and maintaining their nest.

The tidy insects have also created a cemetery on the flat area of the bunker to put their perished companions to rest. Czechowski estimates that layer, a few centimeters thick, comprised over two million dead ants. Interestingly enough, while many ants were seen scaling the 2.3-meter high bunker walls, none were observed on the ceiling. This means that the ants never get near the ventilation pipe that would enable them to return home.

The mound of the bunker 'colony' in close-up. In the background, against the wall, an ant 'cemetery' is visible. (Photo Credit: Wojciech Stephan)

Wood ants are known for their ability to adapt to notably suboptimal living conditions, including dark caves, remote islands, and small closed boxes. However, the foragers have always been in charge of the location of the nest. In this case, the millions of worker ants trapped in the bunker have no choice. But instead of despairing, they are making the best of the situation — a classic example of “when life gives you lemons, make lemonade.”